The most common question we hear about the City of Charleston’s vote to take over the I-526 extension project is “Does this mean the interstate will be built?”

The answer is almost certainly not. Here are two reasons why:

First, there isn’t enough money. The funding remains at least $136 million short, in spite of the impression that State Transportation Infrastructure Bank (SIB) covered the shortfall.

It is critically important that Charleston taxpayers understand exactly what the SIB did, and did not, do.

As background, the SIB has no remaining borrowing capacity and will have none until 2020 or later. Acknowledging this, on Aug. 17 the board voted that a future SIB board should issue bonds and allocate the proceeds to the 526 project. According to the motion, the funding would come “from future capacity of the SIB with the stipulation that prior to providing any additional funding for the project, the SIB will first fully fund the completion of the Florence County projects estimated to be $80 million to $90 million.”

This motion has no legal authority. Public boards may not, by vote, require their successors to take an action at some unspecified time in the future. The funding depends, as it did before the August motion, on the decision of seven members of a board voting, in 2020 or later (the motion did not mention a date), to issue bonds at that time.

Mayor Joe Riley and Rep. Bobby Harrell have glossed over this point, stating that bonding agencies always obligate future revenues. They conveniently confuse two distinct circumstances.

It is entirely different to issue a bond today, (a contractual action), based on future income, (as families do when they take out mortgages), than it is to promise that a future elected body will issue bonds a decade from now, with repayment based on an even more remote and uncertain revenue stream.

That is like trying to add a new bedroom to your house based on a promise that your children will borrow the money when they graduate from college 10 years from now.

The simple fact is that Charleston city taxpayers will be on the hook not only for cost overruns, as DOT Chairman Eddie Adams recently stated in The Post and Courier, but also for the $136 million funding shortfall.

Second, the extension has none of the necessary permits and is not likely to get them for years, if ever. Projects of this size require extensive environmental review, including an Environmental Impact Statement (EIS), a federal wetland permit, a state water quality permit, and a state Coastal Zone Management permit. The DOT has produced a Draft (not final) EIS and sought comments from other agencies. The comments were unanimously negative.

These letters total dozens of pages, but here are excerpts from three agencies.

From the U.S. Department of Commerce, National Marine Fishery Service:

“Our [previous] letter went on to identify four alternatives ... that were prematurely disqualified because of the approach taken for the alternatives analysis. The Draft EIS and public notice offer the same alternatives analysis [e.g. nothing has changed] ... NMFS reaffirms our earlier request that alternatives that focus on improving existing roadways be included through the entire analysis.”

From the S.C. Department of Natural Resources:

“[Because] the project is not ripe for permit review since the NEPA process has not been completed, DNR recommends that no action on the project be taken at this time.”

From the U.S. Environmental Protection Agency:

“Thus, we find that the permit does not comply with the Section 404(b)(1) guidelines, and we strongly recommend that you deny the permit for the project.”

If the city moves forward with the I-526 extension, they will get a crash course in federal and state regulatory programs, and taxpayers will assume responsibility for a project that, at best, will have to be completely redesigned if it is to eventually gain permit approval. This will require years of time and millions of dollars for engineering and design.

These obstacles are not the only reasons it would be irresponsible for the city to take on the project.

The I-526 extension diverts scarce resources from work that is truly important to the region’s economy and quality of life — like adding capacity to I-26 as the opening of the wider Panama Canal approaches, reducing the state’s $20 billion road repair and maintenance backlog, and improving freight rail connections between the port and the Upstate.

But the financial and permitting realities of the I-526 extension are enough to persuade the City Council to do what the county and the DOT Commission have already done — reject this unnecessary, wasteful boondoggle so we can move forward with a transportation agenda that truly benefits the people and the economy of Charleston and of South Carolina.

Dana Beach is executive director of the Coastal Conservation League.